The chemical conjugation of ATTO488 or Sulfo-Cy5 dramatically reduced the tumor targeting capacity of T22-GFP-H6 nanoparticles showing increased accumulation of the nanomaterial in non-target organs such as liver or kidney, in two different CXCR4+ tumor mouse models (Figure 4 and Figure 5) that differ in their CXCR4 expression level (Supplementary Figure S6) and mouse strain. The gene discussed is CXCR4; the disease is neoplasm.